Download or read book The Role of Microorganisms in the Cycling of Organic Matter in Anoxic Marine Environments A Culture independent Approach Saara Suominen written by Saara Suominen and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book On the Role of Bacteria in the Cycling of Dissolved Organic Matter in the Sea written by Robert Edward Hodson and published by . This book was released on 1977 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Microbial Utilization and Transformation of Dissolved Organic Matter in Aquatic Environments from Streams to the Deep Ocean written by Johanna Sjöstedt and published by Frontiers Media SA. This book was released on 2021-07-28 with total page 255 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Microbial Cycling of Marine High Molecular Weight Dissolved Organic Matter written by Oscar Abraham Sosa and published by . This book was released on 2016 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt: Microorganisms play a central role mediating biogeochemical cycles in the ocean. Marine dissolved organic matter (DOM) – a reservoir of organic solutes and colloids derived from plankton is a major source of carbon, nutrients, and energy to microbial communities. The biological transformation and remineralization of DOM sustains marine productivity by linking the microbial food web to higher trophic levels (the microbial loop) and exerts important controls over the cycles of carbon and bioessential elements, such as nitrogen and phosphorus, in the sea. Yet insight into the underlying metabolism and reactions driving the degradation of DOM is limited partly because its exact molecular composition is difficult to constrain and appropriate microbial model systems known to decompose marine DOM are lacking. This thesis identifies marine microorganisms that can serve as model systems to study the metabolic pathways and biochemical reactions that control an important ecosystem function, DOM turnover. To accomplish this goal, bacterial isolates were obtained by enriching seawater in dilution-to-extinction culturing experiments with a natural source of DOM, specifically, the high molecular weight (HMW) fraction (>1 kDa nominal molecular weight) obtained by ultrafiltration. Because it is relatively easy to concentrate and it is fairly uniform in its chemical composition across the global ocean and other aquatic environments, HMW DOM has the potential to serve as a model growth substrate to study the biological breakdown of DOM. The phylogeny, genomes, and growth characteristics of the organisms identified through this work indicate that HMW DOM contains bioavailable substrates that may support widespread microbial populations in coastal and open-ocean environments. The availability of ecologically relevant isolates in culture can now serve to test hypothesis emerging from cultivation-independent studies pertaining the potential role of microbial groups in the decomposition of organic matter in the sea. Detailed studies of the biochemical changes exerted on DOM by selected bacterial strains will provide new insight into the processes driving the aerobic microbial food chain in the upper ocean.

Download or read book An Integrated Understanding of Microbial Roles in Biogeochemical Cycling in Anoxic Lakes written by Patricia Quynh-Giao Tran and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Microbial communities are made up of microscopic organisms: viruses, bacteria, archaea, eukaryotes, and fungi. Their ability to exist under various and sometimes extreme conditions allows them to thrive in all corners of the environment. Aquatic environments cover 70% of the earth's surface and much of it is undergoing drastic human-impacted change. Rises in atmospheric temperature are leading to an increase in surface water temperatures, which leads to a cascade of ecological impacts, including oxygen depletion through physical and biological means. In this dissertation, I demonstrate how microbial communities, particularly bacteria, archaea, and phages (viruses that can impact prokaryotes) impact biogeochemical cycling in anoxic lakes. Using holistic approaches that cover both cultivation-dependent and independent methods, I aim to expand the way we approach studying microbial communities by leveraging interdisciplinary strengths to demonstrate that microbes and phages are interacting members that are highly dynamic in time and space. In Chapter 1 (Introduction), I summarize the role of freshwater lakes in biogeochemical cycling by focusing on the transformations that occur in the water column. For context, I compare and contrast some of the physical features of Lake Tanganyika and Lake Mendota, the two study sites in this work. I then give a broad summary of what is known about microbial and viral function in anoxic lakes. Together, these form the rationale for the next chapters. In Chapter 2, I used physiological and genomic evidence to characterize bacteria that were able to produce hydrogen sulfide under oxic conditions, a process typically associated with dissimilatory sulfate reduction which occurs under anoxic conditions. This work demonstrates and expands the spatiotemporal scope of hydrogen sulfide sources and sinks in the environment. In Chapter 3, I used genome-resolved metagenomics to characterize the potential contribution of bacteria and archaea in Lake Tanganyika, a permanently anoxic lake that happens to be one of the world's deepest and oldest lakes. This revealed that the anoxic hypolimnion of Lake Tanganyika had an extremely high proportion of Archaea, and endemic microorganisms, compared to other freshwater lakes worldwide, giving insight into the interplay between long-term anoxia and evolution. In Chapter 4, I provide a commentary that argues for a holistic way to study biogeochemical cycling: from an organismal and methodological perspective. In Chapter 5, I apply this holistic framework to assess the impact and interactions between phage and prokaryotes on biogeochemical cycling in a seasonally anoxic freshwater lake. We found that the bacterial community was sensitive to deoxygenation but the viral community was not. A broad range of bacterial taxa were infected by phages, but phages were highly specific. Phage-impacted bacteria were active in methane, sulfur, and nitrogen metabolism. Finally, time-series phage activity data showed the dynamic impact of phage-host interactions for nutrient cycling. Overall, the knowledge and framework generated in these studies improves our understanding of complex multi-kingdom species interactions and their associations with microbiology, ecology, and biogeochemistry in anoxic environments.

Download or read book Marine Organic Matter Biomarkers Isotopes and DNA written by J. K. Volkman and published by Springer Science & Business Media. This book was released on 2006-02-09 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: The oceans contain a great biodiversity of marine organisms. They include a rich variety of unusual genes and biochemistries and hence a diverse array of organic compounds ranging from colourful carotenoids and chlorophylls to lipids with structures ranging from the simple to the complex. This volume brings together ten chapters on the occurrence and identification of the lipid biomarkers and of pigments in marine waters. It describes how they can be used in conjunction with stable isotopes and molecular biology to ascertain the sources and fate of organic matter (both natural and pollutant) in the sea and underlying sediments. The authors are each experts in their field and the chapters provide both an overview of the state-of-the-art and knowledge gaps together with abundant detail to satisfy the needs of specialists and non-specialists alike.

Download or read book Dynamics and Characterization of Marine Organic Matter written by N. Handa and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 561 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the past decade the scientific activities of the Joint Global Ocean Flux Study (JGOFS), which focuses on the role of the oceans in controlling climate change via the transport and storage of greenhouse gases and organic matter, have led to an increased interest in the study of the biogeochemistry of organic matter. There is also a growing interest in global climate fluctuations. This, and the need for a precise assessment of the dynamics of carbon and other bio-elements, has led to a demand for an improved understanding of biogeochemical processes and the chemical characteristics of both particulate and dissolved organic matter in the ocean. A large amount of proxy data has been published describing the changes of the oceanic environment, but qualitative and quantitative estimates of the vertical flux of (proxy) organic compounds have not been well documented. There is thus an urgent need to pursue this line of study and, to this end, this book starts with several papers dealing with the primary production of organic matter in the upper ocean. Thereafter, the book goes on to follow the flux and characterization of particulate organic matter, discussed in relation to the primary production in the euphotic zone and resuspension in the deep waters, including the vertical flux of proxy organic compounds. It goes on to explain the decomposition and transformation of organic matter in the ocean environment due to photochemical and biological agents, and the reactivity of bulk and specific organic compounds, including the air-sea interaction of biogenic gases. The 22 papers in the book reflect the interests of JGOFS and will thus serve as a valuable reference source for future biogeochemical investigations of both bio-elements and organic matter in seawater, clarifying the role of the ocean in global climate change.

Download or read book Microbial Response to a Rapidly Changing Marine Environment Global Warming and Ocean Acidification written by Mi Sun Yun and published by Frontiers Media SA. This book was released on 2021-09-24 with total page 155 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Socio Ecology of Microbes in a Changing Ocean written by Matthias Wietz and published by Frontiers Media SA. This book was released on 2019-08-02 with total page 209 pages. Available in PDF, EPUB and Kindle. Book excerpt: Socio-ecological interactions between microbes and associated organisms are integral elements of marine ecosystem dynamics. This Research Topic combines sixteen papers on interactions across the major domains of marine life, including prokaryotes, phytoplankton, macroalgae, cnidarians, viruses and fungi. These studies offer exciting insights into microbial cooperation and competition, holobiont ecology, interkingdom signaling, chemical microdiversity, and biogeography. Understanding such network processes is essential for the interpretation of ecosystem functioning and biogeochemical events, particularly in the wake of climate change.

Download or read book Towards a Mechanistic Understanding of Marine Microbial Ecosystems written by Julia C. Engelmann and published by Frontiers Media SA. This book was released on 2022-01-27 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Interactions Between Macro and Microorganisms in Marine Sediments written by and published by American Geophysical Union. This book was released on 2005-01-14 with total page 391 pages. Available in PDF, EPUB and Kindle. Book excerpt: Marine sediments support complex interactions between macro-and microorganisms that have global implications for carbon and nutrient cycles. What is the state of the science on such interactions from coastal and estuarine environments to the deep sea? How does such knowledge effect environmental management? And what does future research hold in store for scientists, engineers, resource managers, and educators?Interactions between Macro- and Microorganisms in Marine Sediments responds to these questions, and more, by focusing on:? Interactions between plants, microorganisms, and marine sediment? Interactions between animals, microorganisms, and marine sediment? Interactions between macro- and microorganisms and the structuring of benthic communities? Impact of macrobenthic activity on microbially-mediated geochemical cycles in sediments? Conceptual and numeric models of diagenesis that incorporate interactions between macro- and microorganismsHere is an authoritative overview of the research, experimentation and modeling approaches now in use in our rapidly evolving understanding of life in marine sediments.

Download or read book Marine Microbiome and Biogeochemical Cycles in Marine Productive Areas written by Alejandro A. Murillo and published by Frontiers Media SA. This book was released on 2020-01-16 with total page 179 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Structure and Function of Microbial Communities Processing Dissolved Organic Matter in Marine Environments written by Hila Elifantz and published by . This book was released on 2007 with total page 127 pages. Available in PDF, EPUB and Kindle. Book excerpt: The current study added to the growing information regarding the composition of bacterial community in aquatic environments and the role of specific bacterial groups in DOM assimilation. In particular, this study was the first to unfold the relation between structure and function of the bacterial community in the Arctic Ocean, the only cold environment studied in that aspect to date. The molecular study of GH5 revealed the potential of the community for polysaccharides degradation, however, more need to be done to broaden our understanding of the mineralization of these compounds in the marine environment.

Download or read book The Responses of Marine Microorganisms Communities and Ecofunctions to Environmental Gradients written by Stefan M. Sievert and published by Frontiers Media SA. This book was released on 2019-04-05 with total page 295 pages. Available in PDF, EPUB and Kindle. Book excerpt: Marine environments are fluid. Microorganisms living in the ocean experience diverse environmental changes over wide spatiotemporal scales. For microorganisms and their communities to survive and function in the ocean, they need to have the capacity to sense, respond to, adapt to and/or withstand periodic and sporadic environmental changes. This eBook collates a variety of recent research reports and theoretical discussions on the ecoenergetic strategies, community structure, biogeochemical and ecosystem functions as well as regulatory processes and mechanisms that marine microorganisms employ in response to environmental gradients and variations.

Download or read book Linking Microbial Metabolism and Organic Matter Cycling Through Metabolite Distributions in the Ocean written by Winifred M. Johnson (Ph. D.) and published by . This book was released on 2017 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt: Key players in the marine carbon cycle are the ocean-dwelling microbes that fix, remineralize, and transform organic matter. Many of the small organic molecules in the marine carbon pool have not been well characterized and their roles in microbial physiology, ecological interactions, and carbon cycling remain largely unknown. In this dissertation metabolomics techniques were developed and used to profile and quantify a suite of metabolites in the field and in laboratory experiments. Experiments were run to study the way a specific metabolite can influence microbial metabolite output and potentially processing of organic matter. Specifically, the metabolic response of the heterotrophic marine bacterium, Ruegeria pomeroyi, to the algal metabolite dimethylsulfoniopropionate (DMSP) was analyzed using targeted and untargeted metabolomics. The manner in which DMSP causes R. pomeroyi to modify its biochemical pathways suggests anticipation by R. pomeroyi of phytoplankton-derived nutrients and higher microbial density. Targeted metabolomics was used to characterize the latitudinal and vertical distributions of particulate and dissolved metabolites in samples gathered along a transect in the Western Atlantic Ocean. The assembled dataset indicates that, while many metabolite distributions co-vary with biomass abundance, other metabolites show distributions that suggest abiotic, species specific, or metabolic controls on their variability. On sinking particles in the South Atlantic portion of the transect, metabolites possibly derived from degradation of organic matter increase and phytoplankton-derived metabolites decrease. This work highlights the role DMSP plays in the metabolic response of a bacterium to the environment and reveals unexpected ways metabolite abundances vary between ocean regions and are transformed on sinking particles. Further metabolomics studies of the global distributions and interactions of marine biomolecules promise to provide new insights into microbial processes and metabolite cycling.

Download or read book Acquisition Degradation and Cycling of Organic Matter Within Sea ice Brines by Bacteria and Their Viruses written by Gordon Maxwell Showalter and published by . This book was released on 2020 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Marine dissolved organic carbon (DOC) is a major component of the global carbon pool, and thus can have significant effects on global carbon cycling. Within the oceans, DOC is largely regulated by microbial communities, which can serve as both a source and sink of organic carbon. Microbial controls on DOC cycling within sea ice are especially relevant to global processes, as sea ice can act as an inhibitor of exchange between the ocean and the atmosphere while also affecting carbon export to the deep sea. However, how sea-ice communities influence DOC cycling, especially in very cold conditions of winter sea ice, is poorly understood. This dissertation explores how bacterial communities, which dominate winter sea ice, may influence DOC cycling. Chapter 1 presents an introduction of sea-ice microbial communities in the low-temperature, high salinity conditions which characterize sea-ice brines. How bacteria within brines swim in response to temperature, salinity, and chemical gradients in sea ice is presented in Chapter 2, which demonstrates a low-temperature record for directed bacterial swimming and suggests explanations for how bacteria position themselves within brines to access DOC. However, most DOC within the marine environment is too large for bacterial uptake, necessitating degradation by enzymes. Chapter 3 demonstrates bacterial extracellular enzyme activity both in a laboratory setting and in situ, showing growth-dependent enzyme activity down to -8°C and up to 142 ppt salts and across a freeze-thaw cycle within sea ice and sea-surface microlayer samples. Finally, Chapter 4 presents a model of bacterially and virally mediated DOC cycling. This model uses simple differential equations, explained further in Appendix 1, to probe the potential existence of a viral shunt within sea-ice brines by demonstrating the role of bacteriophage in population dynamics of a theoretical brine, suggesting low viral production, high host-specificity, and virally-driven DOC cycling may be common within this environment. The results of this dissertation have implications for the understanding of DOC within polar seas and demonstrate the potential for active DOC cycling mediated by bacteria and their viruses within winter sea ice, which serves as an analog for very cold ice elsewhere.

Download or read book Techniques for the Assessment of Microbial Production and Decomposition in Fresh Waters written by I︠U︡. I. Sorokin and published by . This book was released on 1972 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: The role of micro-organisms in the working of the aquatic ecosystem is fundamental. Through their chemo/photo synthesis and decomposition of organic substances, they contribute both to the availability of particulate organic matter and also to the circulation of nutrients. In recent years, their importance as food for zooplankton has been more clearly recognised, especially in the Soviet Union. Without an assessment of aquatic microorganisms, the full problem of production in a lake cannot be grasped. This book is based on an international meeting of micro-biologists in Leningrad in 1969, and is an attempt to collate and describe the most important methods in this field.